W.W.
I have the Galaxy Note - it's a HUGE phone. However, I can work on it!! LOL!!
Any way - I have the Otterbox Defender on my phone. It does make it bigger and heavier.
IF you want to be able to carry your phone in a wristlet or something other than your hand? Bring the wristlet with you to make sure it fits. If you run and keep your phone in the arm band? Make sure it will fit. It might not.
The otterbox has been AWESOME for me. I'm not a clutz, but I'm REALLY hard on things and my phone hasn't broken yet. This is my 3rd otterbox for a Galaxy!